Our overall goal is to understand how sleep is altered in persons with chronic obstructive pulmonary disease (COPD), and how physiologic changes in ventilation, oxygenation, and sleep architecture influence sleep related symptoms of insomnia, snoring, and daytime hypersomnolence in patients with COPD. We will show how these abnormalities during sleep are associated with quality of life in persons with COPD. We propose to study a sample population of persons with COPD taken from the Sleep Heart Health Study (SHHS) database. This database can provide information on pulmonary function, sleep studies, sleep related symptoms, and quality of life. The SHHS dataset provides a large sample population from which we can use a nested case-control study design to match on characteristics such as age, gender, race, body mass index, smoking history, and presence of sleep disordered breathing. A better understanding of the association of sleep alterations and ventilatory changes during sleep with symptoms and quality of life in individuals with COPD will guide us to areas of intervention to improve morbidity in this population. [unreadable] [unreadable]